‏A second - order reaction has a rate constant of 0.06 M min - 1 . It takes min for the reactant concentration to decrease from 0.13 M to 0.088 M. Select one : O a . 73.4 O b . 7.80 O c . 6.50 O d . 61.2

Choice D. Approximately minutes.

Explanation:

The reaction rate of a second-order reaction is proportional to the square of one of its reactants.

Let denote the rate constant of this reaction. Assume that is the concentration of that reactant at the beginning of this reaction (when .) Because this reaction is of second order, it can be shown that:

.

The question states that the rate constant here is . Hence, . For simplicity, assume that when the concentration is . Therefore, . The equation for concentration at time would become:

.

The goal is to find the time at which the concentration is . That's the same as solving this equation for , given that :

.

.

In other words, it would take approximately minutes before the concentration of this second-order reactant becomes .